For cellular telecommunication network with a base station of each cell, for example a 3GPP LTE network, radio link failure (RLF) performance as well as handover performance is evaluated in challenging mobility scenarios. In particular, scenarios where handover failures occur, i.e. the handover signalling is not transmitted with the desired success rate, is a cumbersome task. A challenging scenario involving users moving at high speed is the so called “high speed train scenario”. This scenario involves users travelling with a speed of 350 km/h in heavily loaded networks consisting of large cells. Another challenging scenario involves effects related to micro cells in urban areas. One of the most serious problems in this case is the corner effect in which a user equipment device could experience a sudden drop of signal level up to 20 dB per meter due to loss of line-of-sight communication when it turns around the corner. Particularly the 3GPP LTE imposes high requirement on the handover performance, thus, it is of significance to find feasible solutions to combat the corner effect. The specification 36.331 of 3GPP discloses handover between eNodeBs and from an eNodeB to another radio access technology. Also other similar telecommunication systems face the same problem. Furthermore, the number of handovers will increase due to the smaller size of micro-cells.
The specification 3GPP TS 36.300, version 9.2.0 Release 9 discloses in its section 10.1.6 behaviour associated to radio link failure (RLF), such as for handover failure. Activity is there described to be resumed by means of explicit signalling between UE and eNodeB, or connection is released and the UE initiates procedure to establish new connection.
WO 2009/048754 discloses neighbour list update for inter radio access technology (IRAT) transition. To facilitate IRAT handover, measurement control information such as neighbour list information is retrieved by the UE from the network.
“Summary of email discussion on handover failure handling” submitted to 3GPP TSG RAN WG2 #61 in Sorrento, February 2008, by NTT DoCoMo Inc. discusses approaches for RLF recovery and whether RLF recovery should be considered as RLF at target cell or at source cell at handover failure.
In such scenarios, where the signal environment may change quickly, and the normal process for performing handover, maybe for a multitude of users more or less simultaneously, may not be sufficient. It is therefore a desire to improve performance in such situations.